Automatic choker for carburetors



Mal-ch23 1926.

4 G. R. SISSON AUTOMATIC CHOKER FOR CARBURETORS FiledJu ly 16, 1923 2 Sheets-Sheet Ta SWIM/l INVENTOR.

6'15 R 5/55 on,

ATTORNEY.

March 23 1926. 1,577,766

I G. R. 'SISSON AUTOMATIC- cHoxER FOR CVARBURETORS Filed July 16 1923 V Z Sheets-Sheet 2 Patented i Mar; 23, .1926.

I UNITEDQSTATES PATENT OFFICE.

GLEN R. SISSON, OF PENDLETON, INDIANA.

AUTOMATIC CHOKER FOR GARIBURE TORS.

Ap'plication filed July 16, 1923. Serial No. 651,871.

I To all whom it may concern:

-Be it known that I, GLEN R. SIssoN, a citizen of the United States, residing at Pendleton, in the county of Madison and State of Indiana, have invented a new and useful Automatic Choker for Carburetors, of which the following is a specification.

It is the object of my'invention to pro: vide an automatic choker for carburetors,

mg starting and warmmg up, and for compensation for temperature variations both 'in 4 the air and in the engine, so that an cfficient mixture under all conditions may be obtained without requirmg special skill on the-part of the operator.

' the air-supply for the carburetor while the ing it"runnlng,

, In the operation of automobiles, man drivers have difiiculty, especially in and just after starting, and most pronouncedly in cold weather, in getting the right amount of air. They'may fail to start by having too much air. They may fail to startby having too little air. They may kill their engines immediately after starting, by opening the choker valve too wide and thus admitting .too much air, especially in cold weather and with a cold engine. Even if they do su'cceed in getting the engine started and keepthey are-apt very quickly to have ineflicient operation 'by reason-of too little air, on account of keeping the choker toodar closed too long after starting.

In accordance with my invention, I control a supply of air for the carburetor jointly by three conditions! the temperature of the engine, the temperature of the air, and the condition of the circuit of the starter motor for the engine; but my invention in some of its aspects requires control by only two of these conditions; I provide a choker valve which, is automatically actuated to cut down circuit of the starter motor is closed, and to increase such supplywhen the starter-motor circuit is opened. I impose upon this control of the air-supply to the carburetor by the starter-motor circuit, a. second control by changes in the temperature of the engme; by

increasmg such air-supply as the engine warms up and decreasing 1t as the englne cools down. This control by temperature,

or more specifically-engine temperature, and starter-motor circuitjointly is broadly the subject of my co-pendingapplica'tion, Serial No. 634,576, filed April 25 1923, in which application the two controlling actions are for regulating the air-supply, especially durshown as exerted through separate valves 1n the branches of a branched air inlet. Ac-

cording to my present'invention-when considered independently of the third control feature to be referred to later, as some of the claims do consider it,the control by engine temperature and starter-motor circuit jointly is obtained through jointcontrol of the same choker valve; but in those claims where the third feature of control by temperature of the air is involved in its broader aspect, my present invention contemplates broadly the Joint control by the air temperature and by either or both of the starter-motor cirolu'lt -and the engine temperature, whether his or b more than one choker valve. This joint control is by a single choker valve thir feature of control is by a device which is responsive to temperature of the air, and

which, specifically considered, acts to limit the extent to which a choker valve is opened upon the interruption of' the starter-motor circuit, so that when the air is cold; such choker valve will not be opened as wide upon the breaking of the starter-motor circuit as when the air"-- is warm, other conditions remaining the same.

The accompanying drawings illustrate my invention: Fig. 1 is a side elevation of an automobile engine equipped with' one form of my invention, with two choker valves, the structure being shown semi-diagrammatically; Fig. 2 is an enlarged sectional detail of the air-control apparatus of Fig. 1; Fig. 3 is a fragmentalside elevation of a different air-control arrangement, wherein a single and. t e ex aust gases from the engine are discharged through an exhaust manifold l3 in the usual way. At least part of the airsupply for the carburetor 11 is,conven1ently derived from the usual stove 15 on the ex-- haust manifold 13, sothat theair will be heated by. the heat of the exhaust gases, though this stove is not essential to my invention. The air-supply pipe 16 for the Y carburetor leads from this stove 15, when is operated by a thermostat 21 mounted on the exhaust manifold. 13 or otherwise res onsive to the temperature of the engine. is thermostat 21 is shown as the usual two-metal strip, arranged so that its free end falls and uses as the temperature of the engine increases and decreases respectively, so that the choker valve 20 Wlll be opened u on increase in engine-temperature and I c osing upon decrease in engine temperature.

- is controlled jointly pressed toward openposition,

and to the solenoid The branch-inlet opening 17, which iscontrolled by the choker valve 20, is shown as getting its air independently of any stove,

though this independence is not essential.

In the main air-supply pipe 16, between the stove 15 and the ranch-inlet opening 17, there is a choker valve .25, which is springas by a tension spring 26, and which may be closed by a solenoid 27. The solenoid 27 is connected in shunt'to the startermotor 28, so that it therewith 'by the usual starter switch 29. When the starter switch 29 is depressed, it completes a circuit from the usual battery 30 'to-the starter motor 28, 27 in shunt to such Thus the solenoid 27 closes the choker valve 25 during thetime the starter motor 28 is in operation, and the sprm 26 opens such choker valve during starter motor.

' the tlme the starter motor is notin operopen as ,far as when the air is 0t. To

ation. l

The extent to which. the spring 26"open's' the choker valve 25, however, varies with the temperature of the air. When the air is cold, the choker valve 25 is not; ermitted to this control, I provide the core 31 of v solenoid with a transverse stop finger 32, which co-operates with acam-stop 33 1:0- tated by a thermostat .34'responsive to the air temperature. The thermostat 34 is also shown as a two-metal'strip, and; is arrange so that its end which is connected to the i cam-stop 33 rises turns the cam-stop 33 in a clockwise direc-j' and falls as. the air temperature rises and falls respectively. This tion when their temperaturerises, toward or to the .poeition shown in full lines in Fig. 2, so t at then the choker valve 25 may be open to the utmost when the solenoid st p .88

is de-energ1zed;-and turns such cam .is hot, this permits a wide opening of the d-the' o in a counter-clockwise direction weaves when the air temperature 'fallsjtoward or to the osition -shown i-n dotted lines in Fig. 2,-so t be opened so far when the solenoid27is deenergized. The stop Fig; 2 in :full lines for t e wide-0'- n pos1- tion of the choker valve 25, an in two dotted-line positions for the closed and the respectively.

In the operation of the arrangement at then the choker valve 25 not fin or 32' is shown partly opened conditions of the choker valve shown in Figs. 1 and 2,-the engine is started in the usual manner, by closing the starter switch 29 to cause the starter motor 28 to turn the engine over. .ever, pays no attention to any choker-valve adjustments for obtaining his starting. The

The operator. howclosing of the starter switch 29 produces the energization of the solenoid 27, which acts to close the choker valve 25 and thus to cut down the supply of air tothe carburetor If the engine is cold, the other choker valve 20 will then be in closed noid makes the very rich mixture required for cold starting. If the engine'is not so cold, the choker valve 20 will .be propor-- tionately open, and may be wide open if the engine has only very recently stopped. As soon as the engine do very promptly, opened, to de-energize both the starter motor 28 and the solenoid 27, The core 31' dro starts, wlnch it will I the starter-switch 29 is position; so that the closing of the choker valve 25. by the soleto cause the choker valve 25 .to open as at as permitted by the cam-stop 33. If the air choker valve 25: because the c'am-sto will be in or well toward its hot position shown in full lines. the air is cold, this permitsa much less wide If on the other hand opening of the choker valve 25; because the thermostat 34 will then have moved the cami stop killing the engine from having a mixture 33 toward or to its cold position shown in dotted lines in Fig. 2. This makes both for efiicient starting and for eflicient operation after starting, without danger of which is either too rich or too lean. If the engine was cold at starting, so that the choker valve 20 was in closed or nearly- .closed'.position, the thermostat 21 acts to open such choker valve 20 as the engine warms up, until such choker valve 20 .is in wide-open position .for a hot engine. Thus ration of the starting motor always cuts own the Supply of air during such starting, trolled partly bythe temperature of the engins and partly by the temperature of the a1r.-.

Referring now to the embodiment; of my but such air supply is also ooninvention" illustrated in Fig. 3: The exhaust manifold 13, the stove 15, the solenoid 27 and its core 31, the starter switch '29, the

starter motor 28, the stop figure 32, the oam- 1 stop 33, and the thermostat 34 are the'same as shown ilrFigs. 1 and 2, save that the solenoid with its associated parts is shown laid on its side; but, as before, the thermostat 34 is so shown that the cam-stop 33 is moved in a clockwise direction upon increase in air temperature andin a counter-clockwise direction'upon decrease in air temperature. Here, however, the air-supply pipe 16 is shown as having only a single air-inlet 40, through the stove 15,-so that the air flow into such air-supply pipe is controlled by a single ch'okervalve 41. The core 31 is con- In consequence, for a given position of the arm 42, the choker valve 41 tends to move in a counter-clockwise direction, to shift the pin 44 toward or to the stop shoulder 45,

.upon increase in temperature; and tends to move in a clockwise direction, to shift the pin 44 toward or to the stop shoulder 46,

' upon decrease in temperature. The thermostat 47 is responsive to variations in temair-supply pipe 16, close to the stove 15, so

perature of the engine; as shown being mounted in a pocket 48 on the s de of the that it will receive heat by rather shortpath metallic conduct-ion from the exhaust manifold 13 which passes through such stove 15.

,In the arrangement shown in Fig. 3-, as 111 the arrangement shown in Figs. 1 and 2,

' ward= wide-open position.

the choking of the air supply for the carburetor is. controlled jointly by the startermotor circuit, the engine temperature, and the air temperature. When the starter switch 29 .is closed, the solenoid 27 pulls its core to the left, ,to swing'the choker valve 41 in aclockwise direction toward closed position. \Vhen the starter switch 29 15.1'8-

noid 27 permits the spring 26 to move the core 31,to the right, to swing the choker valve 41 in a counter-clockwise direction :to-

The extent to which the core 31 thus moves to the right is controlled by the air temperature, acting on the thermostat 34 to control the position of the cam-stop 33 to make such movement of the core towardthe right less when the air iscold than when the air is hot; so that v the hotter the air is, the farther the choker valve 41 will be swung toward its wide-open position. The actual position. the choker valve 41 takes in any of these varlousconditions, however, depends upon the engine temperature; If the engine is cold, the whole range of movement of the choker valve 41, under the action of the solenoid 27 and spring 26 and the limiting effect of the cam-stop 33, will be further in a clockwise direction than when the engine is hot;

so that other things remaining constant, the choker valve 41 is swung to the. left toward or to'widc open position as the engine heats up. If the engine is cold on starting, the

'- action of the solenoid 27 when it is energized will be to move the choker valve 41 substantially to closed position; and the choker valve 41 will move only part way toward open position when the solenoid 27 is de-ene'rgized. On the other hand, if the engine is hot on starting, as from having been stopped only a short time, the action of the solenoid 27 when it is energized is to move the choker valve 41 only part Way toward closed position, but to let it open widerwhen the solenoid is de-energized.

Now referring to the embodiment of my invention illustrated in Fig. 4: The exhaust manifold 13, the stove 15, the solenoid 27 and its core 31, the starter switch 29, the starter motor 28, the stop finger 32, the camstop 33, and the thermostat 34 are. the same as shown in Figs. -1, 2, and 3, and the solenoid and its associated parts is laid on its side but in the reverse direction from that illustrated in Fig. 3; but the thermostat 34 is shown arranged, as before, so that the cam-stop 33 is moved in a'clockwise direc-' tion upon increase in air temperature and in a counter-clockwise direction upon decrease in air temperature to control the extent of opening of the choker valve by such air temperature. Here, as in the case of the arrangement shown in Fig. 3, the air-supply pipe 16 is-shown as having only a single air inlet 40, through the stove 15, so that theair flow through such air supply pipe is controlled by a single choker valve 50. This choker valve 50 is illustrated in Fig. 4 as of the poppet type, whereas the other'choker valves-have all been of the butterfly type; but this is merely to show that my invention is applicable to any type of choker valve, and is not limited to any particular type in any embodiment of my invention. The solenoid 27 is connected, as before, in shunt to the starter motor 28, so that it is controlledjointly therewith by the starter switch 29. In the shunt connection leading to the solenoid 27, however, there is a second switch engine, as by being mounted on the exhaust manifold 13. This thermostat 52, like the others, is shown as a two-metal strip; and

,51, which is operablyconnected to a thermo stat 52 responsive to the temperature of the it is arranged so that when the engineexcceds. a predetermined temperature, the switch-connected end of such thermostat to open the switch51, in which positionit "is shown. In consequence, the solenoid I27 is energized under the control of the starter switch 29 only when the engine temperature is below a predetermined point, or

sufiiciently low so that the solenoid 52 willv close the switch 51; so that when the ene is hot and in condition for easy start-' mg-the operation of. the starter motor'28 will not be accompanied by a choking of the air supply.

Thus in the arrangement shown in Fig. 4,

the choking of the air supply is controlled by the condition of the starter-motor circuit, with a super-control by the temperature of the engine, and the extent to which the choker valve opens is controlled by the temperature of the air.

' I claim as my invention: h

1. Achoking device for the carburetor of an internal combustion engine, comprising a choker valve for controlling air-flow to said choker valve upon'the. deenergization of said electro-magnetico crating means.

3. The combination set forthin claim 2,

' with the addition that the thermostat is responsive to the temperature of the air.

4. A choking device for the carburetor of an internal combustion engine, comprising a choker valve for .controlling air-flow to said carburetor, electro-magnetic operating means for said choker-walve, and-two ther- :mostats responsive respectively to air 'tm 'perature and en ine temperature and controlling said eho er valve jointly with said electro-magnetic operating means.

' 5. A choking device for the carburetor of an internal combustion engine havin a.

starter device, comprising a choker va ve, means controlled jointly with said starter device for moving said choker valve toward closed position while-the starter device is opcrating and for permitting it to move toward open position when the. starter device ceases operating, and a thermostat arranged to control the extent. to whichthe choker valve moves toward. 0 en position upon the stopping of the operation of said starter device. p p

- 6; A. choking: device for the carbur tor of an internal combustion engine havinfi a' v ve,

starter device, comprising a choker means controiled-jointly-with said starter flclosed for moving said choker valve toward device position while the device is electric starter motor and its control comprising a choker valve, electro-magnetic means also controlled by said control switch of an internal'combustion engine v ng an electric starter motor and its controlsw1tch,- 1"

means also contro operating and for permitting it to move toward open position when the starter device ceases operating, and a thermostat res onsive to the temperature of the .air an arranged to control the extent to'whi'ch the choker valvemoves towardopen. position upon the stopping of the operation-of said starter device.

7. The combination set forth'in claim 6, with the addition of a thermostat responsive to the temperature of the engine andexerting a control on said choker valve jointly with the other controlling devices thereof.

8. A choking device for the carburetor of an internal combustion engine having a starter device, comprising means for choking the supply of air to the carburetor, means rendered'operative during the starting of the engine by said starting device for increasing the choking-effect of said choking 8 means, and means for varyin the choking of the supply of air to the car uretor in accordance-with the temperature of the air.

9; A choking device for the carburetor of an internal combustion engine having a starter device, comprising mean for chokingthe supply of air to the carburetor, means rendered operative during the starting of the engine by said starting device for increasing the choking effect of said'choking means,'and meansfor varying the choking of the supply of air to the carburetor in accordance with the temperature of the air and also in accordance'witli the temperature of the engine.

1 10. A choking device .for the carburetorof an internal combustion-engine havln a 'starter device, com rising a single cho er valve for choking t e supply of air to the carburetor, means rendered o rative dur- 106 ing the starting of the engine y said starting device for increasing the chokingefiect of said choker valve, andtwo thermostats responsive respectively to the temperature of the air and engine for controlling said choker valve jointly with: the aforesaid means.

'11. A choking'de'vice for the carburetor of an internal combustion engine ha an and rendered operative during the energization of-the starter motor for moving said: choker valve toward closed posltion, and a 1 thermostat alsoyexerting' a, control on said choker valve.

12."A choking device for the fiburetor:

com rising a choker. valve electro-magnetic p lled by "id control-switch and rendered operative during the energization of the starter-motorfor moving and to the temperature of the swltch,

choker valve toward; poeitiomand :a

thermostat also exerting a control on said.

choker valve, said thermostat'being responsive to the tem erature of the air. 7

13. The com ination set forth in claim 11, with the addition that said thermostat is responsive to the temperature of the en gine.

14. The combination set forth in claim 12, with the addition of a second thermostat res onsive to the temperature of'the engme an also exerting a control on said choker valve. v

15. A choking device for the carburetor of an internal combustion engine, compris-.

ing means for controlling the air inlet-tothe carburetor, and means for governing said controlling means jointly by the temperature of the airand the temperature of the engine. p 16. The combination set forth in ,claim 1, with. the addition that said .thermostatic means is responsive to the temperature of the air. 17. The combination set forth in claim 1,

with the, addition that said thermostatic means is responsive to the temperature of the engine. p

18. Achoking device for the carburetor of an internal combustion engine, comprising a choker valve, electro-magnetic operating meansfor said choker valve, and two thermostatic means for controlling said choker valve ljointly with said electro-magnetic operating means, one of said thermo-j static meansbelng responsive to a1r'tem-- perature andthe other to engine temperature.

a 19. A choking device for the carburetor of an internal combustion engine havin a starter device, comprislng a choker v ve,

-means is responsive to the temperature of;

the air."

21. The combination set forth in claim 19 with the addition that said thermostatic.

means is responsive to the temperature of the engine.

22,. A choking device for the-carburetor of an internal combustion engine havin a,

starter device, comprising a choker va ve, means controlled jointly with said starter device foxmoving said choker valve toward closed position while the starter device is operated and for permittin 1t to move toward open position when t e starter device ceases operating, and two thermostatic means also exerting a control on said choker valve, one of said thermostaticmeans' being responsive to air temperature and the other to engine temperature. I

In witness whereof, I have hereunto set my hand at Indianapolis, Indiana, this 12th of July, A. D. one thousand nine hlin- 1 day died and twenty-three.

- GLEN R. SISSON. 

